This invention relates generally to compacting devices and in particular to devices for crushing or compacting metallic objects.
The various can crushing devices of the prior art included such simple apparatus as an operating handle providing a simple linear ratio leverage force to an article to thereby crush the item. The force applied to the can was generally the common single fulcrum lever arm arrangement for multiplying force which provided a constant ratio of applied force to operating handle force or moment.
Other can crushing devices used various modifications of the simple lever arm force multiplying technique with added features to reduce the crushing force by first collapsing the sides of the can to reduce the initial columnar load stresses.
Some devices also used bell-crank type lever arms for amplifying the force necessary to crush the object. Still other devices used a lever arm arrangement in which the fulcrum point was moved by stages as the can was crushed.
Still other can crushing devices provided brackets which would collapse the sides of the can or provide a rotary or twisting motion as the can was being crushed purportedly to reduce the crushing force.
In all cases, the force being applied to the can was generally constant. That is, the ratio of force being applied to the operating handle relative to the crushing force was constant during the travel of the crushing head or piston throughout the crushing operation.